I just recently built a computer with the HAF 922 case. My problem is that the HAF 922 case is REALLY loud...
I got a EVGA GTX 670 FTW and the 200mm fan on top of the case and infront of the HDD rack is louder than the GPU when it's spinning at 100%...
Is it a problem with the case fans or is it naturally that loud... Or do I have to buy a Fan controller and turn it down...
It's probably your fans spinning at 12v you may want to get a fan controller if you want your case to be quieter.
Make sure there isn't anything(wires) getting in the way of the fans. Also you could unplug the case fans one at a time to isolate the one making noise. If it's a bad fan, you may be able to just get a fan replacement rather that swapping out the entire case just for a faulty case fan. I built a system abut 2 months ago with a HAF 922, and it's quiet. The only time I really hear the fans is when I first power it up.